Help! My Father-in-Law with Parkinson’s and dementia is being mean

5 yrs ago, father­in­law started falling alot and getting ill His wife left him and filed for divorce after 40 yrs. my husband is a only child. after the divorce, he fell and broke his hip. He moved in with us for two years in our home. However, our home was also owned by him. After getting better he went back to his own home. after a few months he fell again and laid on the floor for 3 days. At that point Dr. said he needed 24/7 care. We talked to him asked what he wanted to do. he informed us he wanted to stay in his home. So we left our house of 16 yrs and move our family in. Now all the sudden he wont take his Meds. He is getting mean. He was beating my husband with his walker the other day. We cant get any help. cause he has to many assets. He owns three properties. He is not taking care of the bills. He will not let us help. We have medical POA, and a living will only. And three properties we are trying to take care of. However, Father­in­law has always been a control freak and has always taken care of everything. Now that it is becoming clear, he is not able to continue to care for things he will not give husband POA to do so..Bills are falling behind. Father­ in law cant write out his bills because of the parkinsons, Bmv took his lisc. away a few months ago. He will ask my husband to write out his bills and then gets mad at the amounts of the checks. Then starts taking it out on everyone in the house. He wont go back to the Dr. cause he took his drivers lisc away. We cant keep living this way...We hav no authority to do any thing. Help!!!